Portable rechargable flashlight



June 16, 1953 R. s. COOLIDGE ETAL PORTABLE RECHARGEABLE FLASHLIGHT 3Sheets-Sheet 1 Filed Dec. 21, 1946 INVENTORS' ATTORNEYS June 16,1953CQQLIDGE r 2,642,520

I PORTABLE RECHARGEABLE FLASHLIGHT Filed Dec. 21, 1946 3 Sheets-Sheet 2INVENTORJ ATTORNEYS J1me "1953 R. s. COOLIDGE ETAL 2,642,520

PORTABLE RECHARGEABLE FLASHLIGHT 3 Sheets-Sheet 3 Filed Dec. 21, 1946 QMMM NM lNVEINTQRs- BY 1 awn/7, AA/v.07, M

ATTORNEYS Patented June 16, 1953 PORTABLE RECHARGABLE FLASHLIGHT RogerS. Coolidge, Center Sandwich, N. 11., Harry W. Keely, New York, N. Y.,Reginald S. Smith, Nor-walk, Conn., and Tore N. Anderson, HuntingtonStation, N. Y.

Application December 21, 1946, Serial No. 717,776

8 Claims. 1

This invention relates to a self-contained portable electric light. Moreparticularly the in.- vention relates to an improved portable flashlightwhich is capable of being recharged.

One of the main features of this invention is to provide a novelportable self-contained flashlight which is capable of being rechargedfrom the ordinary house lighting circuit or other ordinarily availablecircuit.

Another particular feature of this invention is the provision of animproved hand flashlight of the ordinary design which may be rechargedfrom an electrical circuit and which has all of the necessaryinstrumentalities carried within the flashlight so that it may berecharged from any ordinary circuit and not be required to be returnedto a, particular house or other lighting circuit or instrument attachedthereto.

Another feature of this invention is to provide a rechargeable portableself-contained flashlight wherein there is a quickly withdrawableelectric attachment plug that may be conveniently connected to a wall orfloor socket, and the flashlight storage portion thereof allowed to berecharged with convenience and ease.

A further feature of this invention is to provide what is known as ahand flashlight of the common size and of transportable nature, and toprovide within the casing thereof a rechargeable battery and a lightweight, simple, electrical instrumentality that is readily connected toany house or ordinary lighting circuit (A. C. or D. C.) and which actsto provide direct current of low voltage for charging the battery.

Another feature of this invention is the provision of an improvedrechargeable, light weight, hand flashlight that is of simpleconstruction, and of low cost, and may be readily carried. Thisflashlight may be made in the pocket sizes or the larger hand carryingsizes.

A still further feature of this invention is the provision of a fillerunit of a rechargeable battery, an electrical instrument fortransforming electrical power from an ordinarycircult to low voltagedirect current for charging the "battery, and of desirable electricalconnections. This unit is available for insertion into the casings ofthe ordinary hand flashlights which heretofore have received only thereplaceable dry batteries.

A particular advantage of this invention is that the total weight of theimproved flash-' light is considerably less than the present hand"flashlights that use dry cells. It. is now possible by the inventionherein, to provide a lighter weight battery and have one that does notswell up and clog the flashlight case thereby eliminate ing thedifliculty of removing swollen dry cells. It is known that dry batterieswill swell if not used. Another particular advantage is that the im.proved battery now employed herein has a substantial indefinite shelflife and uses an alkali electrolyte instead of an acid electrolyte. Thisis very helpful in the event the whole flashlight is crushed or damagedfor any reason, for the alkali electrolyte will not damage the articlesor material it touches, as severely as an acid electrolyte.

Another advantageous feature of the flashl ht device h rein described isthat there is provided a non-leaking liquid, rechargeable battery.

As part of this device, there is provided an improved means forproviding for the automatic cut-01f of the charging current when thebattery has been well charged.

In the preferred construction herein, there is the possibility and theadvantage of using that part of the flashlight empl yed for charging hebattery, for other purposes. For instance, it is possible in theimproved structure herein to disconnect the busbars or electricalconnections leading from the charging instrument to the battery andconnecting it to other apparatus for charging their operating batteries,such for instance, a hearing aid device, or electric movie camera, orthe like.

When it is desired to employ the charging portion of this flashlight forcharging other devices, and at the same time it i desired to use theflashlight, the battery and the electrical charging element or means maybe disconnected and the battery return to its normal position in thecasing and a suitable type of filter mounted behind the battery in thecasing to maintain the battery in flashlight operating position.

This invention provides for a novel type of rechargeable portableflashlight that is capable of being charged from the house lightingcircuit. The designation of such a circuit is for purpose ofillustration for it will be understood that any ordinary circuit that isavailable as long as it is not of too high voltage.

The house lighting circuit of A. C. or D. C. is very satisfactory as itis available most any place. The flashlight may be easily provided withthe type of electrical transforming means that will receive withoutdamage electrical power of 220- volts where most of the house lightcircuits are of 110-volts. Any of these available circuits, industrialor house, will hereafter be understood as coming within the statement ofcommercial or house electric circuits.

In addition when referring to portable flashlights, the term isunderstood to include the ordinary hand flashlight of small, pocketsize, hand lantern type or the like, and the shape of the casing may beas desired, tubular, rectangular, or otherwise.

Further advantages and improvements will be noted in the followingdescription as supplemented by the disclosure in the drawings, wherein:

Fig. 1 is a sectional View of a flashlight case showing a lamp andreflector and some of the electrical connections;

Fig. 2 illustrates the flashlight apparatus partially withdrawn from thecasing and in battery charging position;

Fig. 3 is a top plan view of the battery and the I charging element andelectrical connections therefor, all forming a unit which is slidable inthe casing taken nections of the flashlight with the charginginstrument;

Fig, '7 is a sectional view of a valve for each section of the batterywhich permits gas under pressure to leave the top of the battery butwhich prevents the leaking of the electrolyte;

Fig. 8 is a side view of a flashlight operating unit which may beinserted in a casing now owned or possessed by a user;

Fig. 9 shows the unit illustrated in Fig. 8 in place in the ordinarycasing owned by a user;

Fig. 10 is a modified wiring diagram of the unit and shows the batteryin dotted lines;

Fig. 11 is a side View partly in section, showing means for opening theelectrical circuit when the battery has been sufficiently charged,thereby forming a cutofi; and.

Fig. 12 is a View of an adaptor usable to attach electrically forcharging the battery of a device other than the flashlight.

Referring nowtc these drawings, there is provided a suitable type ofoutside casing 15, preferably tubular, of what is now commonly known asa hand flashlight. A suitable type of head 16 is shown for closing oneend of the casing l 5. This head carries an electric lamp I! which issuitably positioned in a reflector l8. This head also carries a lens Hi.In addition, it is preferred to have the lamp mounted so that it ismovable in respect to the reflector to thereby vary or change the focusof the light beam at will. Such movements may be accomplished by movingeither the lamp or the reflector.

The other end of the tube is provided with a suitable cap 20 which maybe of any desired shape and material so long as it readily withstandsusage. It is preferred to have this cap 20 made of transparent material,such as plastic or other like material, so that the terminal ends of thepower recharging unit as assembled in the tube may be seen thru the cap.In some instances it may be desired to have this cap 20 fastened to thetube l5 by any suitable means, such as a wire or cord 2 l, or anyflexible means so that t e p 4 will not be lost while it is removedduring battery charging operation.

Part of the electrical connections in the casing are readily noted inFig. 1 wherein the base contact 25 of the lamp I! will engage contact 25when head I6 is assembled in position on casing l5.

An electrical connection 26 herein preferred in the form of a channelshaped bus bar, is provided with a spring end 21 for engaging thereflector !8. This type of engagement allows the head I6 to be screwedinto position on the casing 15 and provides for continuous contact ofend 21 with reflector IS. A second bus bar 28, preferably of the samestructure and design, connects contact 25 with a spring portion 29 of ahand switch 30. This spring portion 29 is connected to a second part 3!of a bus bar leading toward the rear of the casing. The switch 33 isprovided with a button 32 for pressing to close the switch 33, and witha sliding button 33 which may be moved forward to close the spring 29 onto the bus bar portion 28 for holding the switch closed without keepingthe users fingers pressing on button 32. This type of switch 30 is theusual type employed in flashlight devices.

It is preferred that the bus bars 26 and 3| extend to points near theend of the tube l5; These connections or bus bars may be of anyparticular design but are preferred to be provided in the forms shown inFig. 5 of channel construction so that contacts carried on the batterywill easily and firmly engage therewith and be slidable there in. Atsuitable points in the bus bars, there are provided sections ofinsulation 35 so that during charging of the battery, no current wouldreach the switch 30 nor the lamp I1.

In providing suitable means, in this instance, a battery, for supplyingelectrical'power to the lamp I! and for providing an instrumentality forrecharging the battery, reference is particularly made to Figs. 3 and 4,wherein there is shown a battery 36 and a battery charging means 3! andterminals or prongs 38 which are adapted to be plugged into a houselighting circuit. It is preferred that the battery 36 and the charginginstrument 3'! and the terminals 38 be mechanically connected togetheras well as electrically connected for the purpose of providing a unit,which is readily removable from the casing I5,

for repair or replacement of any of the parts. Instead of providingprongs38 for the electrical connections, it will be understood thatthere may be sockets to receive plug prong electrically connected to acommercial circuit.

In providing the type of unit here noted, the battery 36 is providedwith electrical conducting arms 39 which carry contacts 40 that engageand are slidable and are guided in the bus bars 26 and 3!. Conductors 4!and 42 lead from a base 43 through pivot points 44 and 46 for conductingthe charging current to battery 36. Preferably, this base carries theprongs 38 for plugging into th house electric light circuit. The pivotpoints at 44 and 46 are preferably of the snap type so that they may bereadily connected or disconnected.

In using electrical power from an ordinary circuit and for changing thatpower to low voltage direct current for charging the battery, a suitableelectrical instrumentality is provided. In the form herein preferred,there is an electronic means or tube which is adapted to be carried inthe flashlight casing so that the flashlight battery may be rechargedfrom any house lighting or available circuit.

For this purpose a preferred type of tube, the connections of which areshown in Fig. 6, is provided. Such a tube may be any one of thefollowing tubes: 117Z6, 50Y6, or 45Z3. It will be noted that a featurein using such tubes is that the filament does double duty in its new useherein. :Such doubl duty is that it first acts as a resistor to heat thecathode and then it acts as a voltage dropping resistor. When it isdesired to start the tube into operation, the filament of the tube isheated. For that purpose a small switch 41 is provided to connect thatportion of the tube across the house lighting circuit for a shortinterval of time.

It has been found that a suitable electronic tube 31 of any of the typesreferred to having particular operating characteristics is satisfactoryfor the purpose. This tube receives the 110- voltage or other voltagepower from the .house lighting or other circuit and if the lightingcircuit is alternating current, it will transform that current intodirect current, and it will reduce the voltage to a desired figure. Ifthe house lighting circuit is direct current and the plug is inserted inthe circuit in the wrong direction, the filament of the tube will glowwhile connected across the lighting circuit but will not glow when theswitch 41 is opened. The terminals of the plug should then be reversedand the instrument will operat normally to charge the battery. Theelectronic tube, Or tubes, may be installed to produce 50 to 200milli-arnperes charging current per tube for this or other purposes.

In providing the improved electronic instrument for receiving theelectrical power and for modifying it to give the low voltage directcurrent for charging the battery, it i understood that instruments otherthan the types referred to may be designed to obtain the desiredresults. In the instrument employed here, it is preferred that there bea filament which is first used as a resistor to heat the cathode toplace the instrument in electrical operation, then the filament is usedas a voltage dropping resistor, and as a regular cooperating filamentelement of an electronic tube.

It will be seen that battery 35, tube 31 and base 43 may be readilyremoved as a unit from the flashlight casing so as to change tubes whendesired or to make any repairs.

In the normal charging of the battery, it is desired to remove cap andto pull the unit out until the battery 36 shows, as indicated in Fig. 2,and the end of the casing I5 is allowed to drop down and touch thefloor, or if the house socket is above table height, the head [6 of theflashlight may rest on a table to preferably give a position illustratedin Fig. 2. In order that the battery shall not be pulled out too far, asuitable stop 49 or any other adaptable means, may be provided forarresting the withdrawal of the unit. This stop is preferably such thatit may be withdrawn so that the whole unit may be easily taken out ofthe casing for repairs or for other purposes. It is also desired thatthe bars 4| and 42 be insulated. A suitable insulation is shown in partat 5| in Figs. 2 and 3. It is desired that no portion of the electricalcircuit, such as the main switch, shall be free to cause any electricalshocks to the user.

It is to be understood that the charging of the battery may beaccomplished by leaving the unit assembled in the casing. It ispreferred, however, that the charging shall be accomplished with part ofthe unit withdrawn as shown in the position illustratedin Fig. 2 so thatif the electronic means 31 gives off appreciable heat, it may beradiated without being required to be absorbed by the casing l5, or byproviding the interior of the casing IS with suitable asbestos or otherheat resistant lining to thereby prevent any damage to the casing.

In carrying out the charging of a wet battery, preferably of the ovaltype, as shown, in the preferred manner, it will be noted that thebattery 36 will be in a tipped position. This is advantageous so thatthe spaces above the electrolyte will communicate with plugs 52 and 53to allow any gas which may develop and be under pressure to escape fromthe battery but will prevent the electrolyte from leaking from thebattery. Any suitable type of apparatus may be employed for thispurpose, but it has been found that these plugs 52 and 53 have shownsatisfactory results.

, A section of one of these plugs is shown in Fig. '7,

wherein a passageway 54 connects to the space above the electrolyte. Theupper end of the passageway 54 connects with a channel 56. A rubbercollar 51 is provided in this channel and is tight fitting in thechannel 56 so that liquid cannot come out of the battery except underexcessive pressures but gas under pressure may move between the surfacesof the rubber and the channel 56. Thus, there is provided in a portableflashlight, a non-leaking, rechargeable wet battery.

In the portable flashlight device herein, it is desired to providesuitable means for modifying or rectifying the electric power from thehouse or other circuit and for reducing the voltage thereof so that alow voltage direct current will be impressed upon battery 36.

Heretofore, it has been known to provide a small motor generator set butthese devices are heavy and complicated and are not suitable in anymanner for hand, portable flashlights, or for the relatively smallflashlights which a person may readily carry.

In the present invention, it has been found desirable to provide anelectronic tube in which the parts thereof are provided to cooperate tosupply the desired voltage and current for charging operations. In thepreferred type of electronic tube, which has proved satisfactory in thistype of apparatus, there is provided one or more filaments 58 and 59. Insome tube types, one such filament is often satisfactory. In startingthe tube, the starting switch 41 is closed, thereby passing the houselighting circuit through the filaments 58 and 59 to heat them and thusbring the tube 31 into operating condition to impress on lines or busbars M and 42 the direct current at the desired voltage. When thesefilaments have been heated sufficiently, the tube 31 starts its normalfunctioning and the switch 41 is opened upon releasing it.

For the purpose of further detailed explanation of this improved batterycharger, and in stating the theory of operation insofar as it is nowunderstood, the following detailed description is made when employing,as an example, the use of a 50Y6 tube operating on 117 volt, 60 cycle A.-C. source of electrical supply.

It will be noted that filaments of the tube are placed across the linesby pressing switch 41, and this immediately starts to heat the cathodeso that thermionic emission may take place.

At the instant of closing the switch, an inrush current of the order of500 milliamperes flows through the filament (or heater element,socalled) which is connected between points 2 and I in Fig. 6. Thisinrush current is due to the low cold resistance of the heater(approximately 200 ohms). This may cause a bright glow in the supportwires due also to this high inrush current. The heater resistance, in amatter of one to three seconds, increases to approximately 500 ohmsresistance, and thus limits the current flow at 110 volts to 200milliamperes, which is not dangerously close to the burn-out currentvalue for the support wires. Furthermore, since the heater wires willtolerate much higher currents than the support wires, there is even lessdanger of burning out said heater wires.

After the cathode and associated heater structure comes up to a brightred heat, an indication is thus given that it is no longer necessary tohold switch 4'! closed, and the switch may accordingly be released.

When the switch is open under the above conditions, the continued redglowing of the cathode is an indication that the battery is charging. Ifthe charger is operated from a 120 volt D.C. supply main and the plug isincorrectly polarized (that is to say, plugged in so that the plate ofthe tube is not connected to the positive side of the line) then theheater element will not continue to glow, thus giving an indication thatthe unit is not connected properly, and that the plug must be reversed.

As mentioned above, the switch 4? is left closed only long enough tothoroughly heat the cathode and furnish enough electron emission toallow the current to flow from the plate to the cathode during theportion of the applied alternating current cycle when the plate of thetube is positive with respect to the cathode. The point at which a redglow is observed is the same as that at which satisfactory electronemission is occurring.

Since current will flow through the tube (and, of course, the batterywhich is in series with the plate) only when the plate is positive withrespect to the battery, a pulsating direct-current (of the order of a100 milliamperes for a series of batteries) is caused to flow throughthem, thus charging them. Thus, charging can be accomplished with thiscircuit until the series of batteries reaches a back voltage ofapproximately 12 to 15 volts, at which time the tube and heater will notbe sufficient to maintain the cathode emission at a high enough value tokeep current flowing through the tube and batteries.

After the switch 47 is opened, the voltage drop through the tube (tuberesistance is sometimes called D.-C. plate resistance) is automaticallyplaced in series with the heater resistance and the battery resistanceto limit the current flow. Current, when operated from 117 volt 60 cyclesupply, flows only during the half-cycle when the plate is positive withrespect to the cathode. The heater element is maintained at atemperature suitable for electron emission by the thermal lag in thecathode and heater structure.

The battery load in electron tube charging circuit is a very small partof the total circuit resistance, and the back E. M. F. up to 12 to 15volts approximately represents only about 10% of the total voltage dropthrough the circuit, and thus, in effect, is negligibly small.Conversely, if the battery size is reduced, providing it can tolerate100 milliamperes, the circuit still remains operative. If by chance thebattery is short circuited, the tube will not be injured, but willcontinue to remain operative.

In the preferred tube 3! there is provided a base 60 which has thevarious prongs numbered By employin this type of electronic instrumen 1tality or tube, it has been found possible to provide an efficient, lowcost, light weight, rugged,

portable flashlight that is rechargeable from any house lightingcircuit.

In the present preferred form of incorporation of elements to providethis improved flashlight, it is desired to have the battery and chargingmeans and elements to connect to the house lighting circuit removed asone unit. Itwill be understood, however, that these may be changed andimproved to meet different types of uses and conditions. For instance,the battery may be mounted in the casing so that it is not movableexcept for replacement purposes and flexible wire connections employedto connect it to the tube and to the base.

Referring now to Figs. 8, 9 and 10, there is illustrated a combinationof elements preferably comprising a battery and special electronic tubeand modified electrical connections. Thiscombination comprises a fillerunit which any person may purchase separately and insert in theflashlight tubing or casing or holder'which he now owns and which wasoriginally purchased to hold dry batteries.

In this type of unit, the battery 36 is provided with an end contact 6!which will engage the base 24 of a lamp. The tube 31, with its base 50,is a tube of special characteristics andis mounted on the head 43 which,in this instance, is provided with prongs 38, but which head may beformed as a socket so as to receive suitable prongs of a connector froma commercial electric circuit. 7

Suitable electrical connections between the tube and the battery may beemployed and are here shown as the bars 4! and 42. In this instance,these are directly connected to the battery.

Referring now to Fig. 9, it will be seen that the battery 36 is mountedin the well known casing 62 and provides for the contact iii to engagethe base of the lamp. Closing cap 20 in this instance, includes a spring33 which will force the head 43 to the left for the purpose of keepingcontact Bl in engagement with the base 24 of the lamp. In

the event it is desired to provide a cap 2!] with-' with each other, asnoted in the wiring diagram in Fig. 10, although in many instances onlyone of them is needed. The casing 62 is provided with a suitableinsulating sleeve 66 which is of shorter length than casing 62 and whichthe contacts 64 will engage when the unit is moved to the right to takethe position shown in Fig. 2 for charging the battery. Thus, there willbe no danger of shocks tothe owner of the flashlight while the batteryis being charged.

Referring now'to Fig. 10, there is a modified form of wiring diagramdifferent in few respects to that ofFig. 6.

The outline of battery 36 is 7 shown in dotted form and is representedat $1 for clearness of the wiring diagram.- The tube 1 3.1 one f the tpes r ierr d o so a to have definite chara teristics o fi he ne e ethere is a defi ite v l a e and a fi te o e t equiremen he filament t ad. .9 o th be he p vid d t btain th d s red c ar in vo ag a d current.These filamen s act i h beginning a heat rs as note above when the starn tc .1 is closed. and a erw ds upon th o e in oi switch 41 they not asro p n r istors an as the filaments n th tub 3 Therei e. the ube 31 isconstructed to ha e one r more filamen u ts, depending upon he iunotonel re ui e-- ments of the tube and the voltage desired for itsparticular install tion- In the event t is se ra operating or filler nitof a lashli ht is nserted n e a in w ic is mad o a non cond ot r or uale mate: rial such as p astic, or the like, it will be desi ab e to usehe ele tr a n ect s l trated in Fi 9 a av the top o duc o s 54 en a ethe lone tudineu nnector unn to he rear of the se fr m the ht ha d d o ih 30 within he cosine. th by c m letin t ircu at intervals s he s i c 3is perated f desire he l r ca onn c ion of the unit to he lamp a d thr uh t swi ch 3 and ack t t e ne ative s d o e atte y ay b complished in aot er su table mannern assemblin theu t n h casi sh w i i .9. any suitle c nst uc n a e e plo ed to maintain the un t oin movin c cula lyespect to th as n Qne ma ne of e om p h ng t s res l s to ov de abl xeni s f nsul tio pie 6.6 so that t e ex ensi ns st add e ach ide ofontacts 54, thus holding them in position to preyent rel tive rota ionThe insulation piece .576 is preferably d finitely held in position inthe threads at the right hand end of the casing. Another means ofaccomplishing this same result wouldbe to have spring members extendin fo the bo y of battery 36 so they would engage any groove, or grooves, inthe casing 52 itself. When the unit is inserted in a plastic case, suchspring members would be adap d to eng ge any longitudinal humpordepression in the casing, thereby preventing a relae tive rotarymovement between the case and the unit. In some designs of plasticcases, an clone trical conductor is riveted longitudinally to the insidethereof, and it is desired that the spring members willhave insulationon their ends and will engage each side of the electrical conductor toprevent any relative .rotary motion between the casing and the unit.Thus, the conductors and switch means for the units when assembled inplastic cases will be retained in proper operating position.

It will be noted that this type of filler unit to be inserted in thepresent casings, originally designed for holding dry batteries, issimple, easily handled, and readily assembled into the casings which theuser or owner already has.

Referring now to Fig. 11, there is illustrated one form of means forautomatically disconnecting the charging current to the battery. In sometypes of batteries, it is desirable to have the charging currentimpressed on it for only a def.- inite time. Most alkali wet batteries;being charged to their capacity for receiving electricity, cause theelectrolyte to gasify to some extent. It is desirable to open thecharging current circuit then .or shortly after gassing starts and hasbuilt .up a definite pressure in the battery. In the type of batterywhich does not start gassing until 10 charging has been substantiallycompleted, the pressure will then buildup and charging will continueuntil'pressure within the battery operates to automatically open thecharging circuit.

In the disclosure herein, there is shown a preferred form of employingthis pressure to open the c rc t o the e tterv an for automaticallyopening the electrical power to the tube. The preferred means for thispurpose includes a bellows or pressure membrane "Ill, Fig. 11, which maybe of any desired flexible or plastic material which pr fe a p lses opush he sprin lever l hat arries an e eot ieel eonouoto h preferably ismolded in the side of the battery casing and whi h connects to the up nof the b y at contact 13. The end of wire 12 engages conteot l wh ch nol is in e g m t with contact 76 which is carried by a suitable bracket17 th ele t ically nnects h co act 6! t a n a es th base. o amp lh w t sie r d construction th circu t l a t m al be open d by rea on o pre surde op d i th battery when the battery has become substantially tullycharged. In opening the circuit, the circ i throu h th fi amen or fi m nin the tube will also be opened and these filaments will cool off-andthe pressure in the battery will ree duo or e released, whatever typ ofbattery is employed, and the contacts '14 and 16 will return o en a i gposition, but the tube 31 will not operate when these contacts againclose because the filaments have been cooled off and can only be startedagain in this type of device by clos ing the starting Switch 4'! to heatthem to a point of operation.

In some types of batteries, they may be provided with a suitable type ofporous vent so that the pressure will slowly decrease therein, therebyallowing contact 74 to become reengaged with contact 16 to close thatpart of the circuit and be ready for operation when the tube filamenthas again been heated.

Therefore, the battery will be automatically disconnected on chargingwhen it has been substantially charged to its capacity. This is a greatadvantage as the life of the battery and the flashlight will beprolonged to a very large extent.

With this type of battery which automatically disconnects the chargingcircuit when the battery has been recharged .to substantially itscapacity and the tube 31 no longer glows and the flashlight remains inposition shown in Fig. 2, the observer can readily see that the charginghas been completed and the flashlight ready for reassemblingand'operation. Thus, the user does have an indicator readily observablein that the tube will be glowing during charging and will be black ornon-glowing after charging has been completed.

In the broad aspects of this invention, it will be noted that there havebeen provided a flashlight lamp and a rechargeablenon-leaking batteryconnected in .circuit with a switch for flashin the lamp o and .o i- Inaddit o e e is providedan electrical means or ec in e cical power fromthe ordi a or h u lighting circuit and ;,for l'ei tifying or modifyingit and limiting the current flow thereof to a satisface Y amount fo imess di u t On to the battery ior recharging purposes.- This combinationof elements or constituent parts may be held together in any desiredfashion to provide Proper functioning and cooperation in operation, andfor easy repair or replacement. In the preferred i rhi the e el me ts am d in a casing which is easily handled and which provides properswitching means for having each element perform its desired function.

This improved flashlight, as disclosed herein, may be charged fromeither a direct current or an alternating current lighting circuit. Whenthe circuit is direct current, the battery is easily charged byreversing the prongs 38 if the tube ceases to glow when the switch 41 isopened.

It is also to be pointed out that there is a great advantage in aportable hand type flashlight to have a rechargeable battery thatemploys an alkaline electrolyte instead of an acid electrolyte. This isadvantageous in the event the body of the battery becomes defective.Such an alkaline electrolyte will not damage and eat away parts of thecasing, or materials which it may touch, to the extent that any acidelectrolyte will.

The improved portable, rechargeable, hand flashlight may be made invarious sizes from pocket size up, and may be charged from any handy,commercial electrical circuit whether alternating current or directcurrent and does not require being returned to a particular type ofpower rectifying circuit or apparatus in order to be recharged. By useof the improved type of non-leaking wet battery, the life of theflashlight has been materially improved and the storage or shelf lifedoes not create changes in the various elements constituting theflashlight.

Many changes and modifications may be made in the several preferredforms illustrated and described herein but such changes andmodifications are considered as coming within the scope of thisinvention, as outlined in the following claims.

The invention claimed is:

l. A portable rechargeable lighting device, comprising a casing, anelectric lamp therein, a rechargeable battery, a switch electricallyconnected in a circuit with said lamp and said battery, an electronictube removably mounted in said casing for supplying charging current tosaid battery and for receiving current from a house lighting circuit,said tube having a filament therein, and a switch in circuit with saidfilament and the house lighting circuit for heating said filament tocondition said tube for operation and thereafter to be opened, a part ofsaid tube thereafter operating as a voltage dropping resistor.

2. A portable flashlight, comprising a casing, a lamp mounted withinsaid casing, a rechargeable battery carried by said casing and adaptedto be slidable therein, an electric circuit maintainable between saidbattery and said lamp, a switch in said circuit for supplying power fromsaid battery to said lamp, a base carried by said casing, electricalprongs extending from said base for connecting into a house lightingcircuit, an electronic tube carried by said base for receiving powerfrom the house lighting circuit and for providing low voltage directcurrent for charging said battery, electrical connecting means betweensaid tube and said battery, and a filament in said tube responsive toinitial current for heating itself and thereafter to act separately as avoltage dropping resistor to provide low voltage current for charging.

3. A portable flashlight, comprising a casing, a lamp mounted withinsaid casing, a rechargeable battery carried by said casing and adaptedto be slidable therein, bus bars carried by said casing, contacts onsaid battery having slidable 1'2 contact with said bus bars therebymaintaining an electrical circuit between said lamp and said battery,said bus bars also acting to guide the sliding of said battery, a switchin said circuit for supplying power from said battery to said lamp, abase carried by said casing, electrical prongs extending from said basefor connecting to a source of electrical power, an electronic tubecarried by said base for receiving the electrical power and forproviding-low voltage direct current for charging said battery, andelectrical connecting means between said tube and said battery.

4. In a portable flashlight, the combination of a tubular casingprovided with electrical bus bars extending most of the length thereof,a switch for opening and closing one of said bus bars, a head providedfor engagement with one end of said casing, a lamp carried in said headand electrically connected to said bus bars, a non-leaking rechargeablebattery slidable into said casing, contacts carried on the side of saidbattery for engaging said bus bars, a base provided with prongs forinsertion into a house lighting circuit socket, an electronic tubemounted on said base for receiving power from said house circuit and fortransforming said power to low voltage direct current for rechargingsaid battery, a switch for temporarily connecting the filament of saidtube across the house lighting circuit until said filament is heated,part of said tube thereafter operating as a voltage dropping resistor,and means joining said base and said battery for maintaining the same inassembly in said tube or in chargeable position, said base and said tubebeing withdrawn from said casing during charging.

5. In a portable flashlight, the combination of a casing, a lamp in saidcasing, an electrical rechargeable means carried by said casing andconnected to said lamp for supplying electrical power thereto, a lampswitch electrically connected to said lamp and said rechargeable meansfor controlling the power supply to said lamp, an electrical device insaid casing and connected to said rechargeable means for controlling thecharging thereof, contacts carried by said electrical device to beconnected at will to an electrical charging circuit, a switch associatedwith said electrical device for connecting an element in said device inshunt with the electrical charging circuit to have said elementseparately and first act as a resistor for heating itself, said switchopened after the heating to have said element connected in series withone side of said charging circuit to separately and secondarily act as avoltage drop resistor to provide proper charging voltage through saiddevice to said rechargeable means.

6. In a portable flashlight, the combination of a casing, a lamp in saidcasing, an electrical rechargeable means carried by said casing andconnected to said lamp for supplying electrical power thereto, a lampswitch electrically connected to said lamp and said rechargeable meansfor controlling the power supply to said lamp, an electrical device .insaid casing and connected to said rechargeable means for controlling thecharging thereof, contacts carried by said electrical device to beconnected at will to an alternating current house lighting circuit, aresistor element forming part of said electrical device, a switchassociated with said electrical device for connecting said resistorelement in said device in shunt with the electrical charging circuit tohave said element separately and first act as a resistor for .heatingitself, saidswitch opened after the heating to cause said resistorelement to be connected in series with one side of said charging circuitfor acting separately and secondarily as a voltage drop resistor inorder to transform the alternating current to direct current and toreduce the voltage for charging said battery.

7. A portable flashlight comprising in combination a tubular casing, anelectric lamp mounted in one end of said casing, a rechargeable batterycarried in said casing and electrically connected to said lamp forsupplying current thereto, a lamp switch for controlling the electricalsupply to said lamp, a first electrical circuit having therein said lampand said battery and said switch, an electronic tube carried within saidcasing, a second electrical circuit having connected therein saidelectronic tube and its connections to said battery, a pair ofelectrical terminals carried by said tube and adapted to be connected toa house lighting circuit for recharging said battery, a cap for fittingover the other end of said tubular casing to enclose said terminals whensaid tube is not connected to a charging house lighting circuit, saidtube having a filament to be connected to said lighting circuit, and aswitch connected in said second circuit for temporarily connecting saidfilament in shunt with said house lighting circuit to heat said filamentand then to open to allow said filament to automatically be connected inseries with said house lighting circuit and to have said filament reducethe charging voltage and to convert the house lighting circuit to directcurrent.

8. A portable flashlight comprising a tubular casing, an electric lampmounted in one end thereof, electrical bus bars carried on the inside ofsaid casing and having said lamp in circuit therewith, a two compartmentrechargeable battery carried in said tubular casing and having contactsengaging said bus bars, one compartment of said rechargeable batteryholding the battery electrolyte, a battery switch mounted in the othercompartment and normally being closed and subject to excess gas pressurein said electrolyte to be pressed open, a lamp switch for controllingthe electrical supply from said battery to said lamp, an electricalcircuit having therein said lamp, said rechargeable battery, saidbattery switch and said lamp switch and said bus bars of length topermit said battery to have predetermined relative movement to saidcasing, an electronic tube movably mounted in said casing and beingelectrically connected to said rechargeable battery for charging thesame from a house lighting circuit, said rechargeable battery and saidtube being mechanically connected together to permit partial withdrawalfrom said casing when desired to connect said electronic tube to a houselighting circuit, terminals carried by said electronic tube to beconnected to said house lighting circuit, a filament in said tube fortemporarily acting as a resistor for heating itself and thereafteracting as a voltage drop resistor for correctly charging said battery, atube switch for closing said filament in shunt with the house lightingcircuit and when open after heating said filament to place said filamentin series with said lighting circuit to have said filament act as avoltage drop resistor.

ROGER S. COOLIDGE. HARRY W. KEELY. REGINALD S. SMITH. TORE N. ANDERSON.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 1,034,108 Halbleib July 30, 1912 1,230,004 Meikle June 12,1917 1,267,199 Ferguson May 21, 1918 1,506,302 Hopkins Aug. 26, 19241,506,303 Hopkins Aug. 26, 1924 1,528,709 Trimble Mar. 3, 1925 1,596,131Vorberg Aug. 17, 1926 1,717,563 Hull June 18, 1929 1,861,789 Davis June7, 1932 2,176,479 Willis Oct. 17, 1939 2,293,284 Emanuel Aug. 18, 19422,425,743 Knight et al. Aug. 19, 1947

